JPWO2019216017A1 - Image display device, projection optical system, and image display system - Google Patents

Abstract

The image display device according to one embodiment of the present technology includes a light source, an image generation unit P, and a projection optical system 15. The image generation unit modulates the light emitted from the light source to generate image light. The projection optical system has a lens system L1 and a concave reflection surface Mr3. The lens system is configured with reference to a reference axis at a position where the generated image light is incident, and has a positive refractive power as a whole. The concave reflecting surface is configured with reference to the reference axis, and reflects the image light emitted from the lens system toward the object to be projected. Further, the concave reflecting surface reflects at least a part of the light rays contained in the image light incident on the concave reflecting surface in a direction intersecting the direction along the reference axis at an angle of 80 degrees or more.

Description

The present technology relates to an image display device such as a projector and a projection optical system, for example.

Conventionally, a projector is widely known as a projection type image display device that displays a projected image on a screen. Recently, there is an increasing demand for ultra-wide-angle front projection projectors that can display a large screen even if the projection space is small. By using this projector, it is possible to project a large screen in a limited space by hitting the screen diagonally and at a wide angle.

In the ultra-wide-angle projection projector described in Patent Document 1, the screen shift that moves the projected image projected on the screen is possible by moving some of the optical components included in the projection optical system. .. By using this screen shift, fine adjustment of the image position and the like can be easily performed (paragraphs [0023] [0024] in the specification of Patent Document 1 and the like).

Japanese Patent No. 5365155

It is expected that projectors that support ultra-wide-angle lenses will continue to spread in the future, and there is a demand for technology that can realize high-quality image display.

In view of the above circumstances, an object of the present technology is to provide an image display device, a projection optical system, and an image display system capable of supporting an ultra-wide angle and realizing high-quality image display.

In order to achieve the above object, the image display device according to one embodiment of the present technology includes a light source, an image generation unit, and a projection optical system.
The image generation unit modulates the light emitted from the light source to generate image light.
The projection optical system has a lens system and a concave reflection surface.
The lens system is configured with reference to a reference axis at a position where the generated image light is incident, and has a positive refractive power as a whole.
The concave reflecting surface is configured with reference to the reference axis, and reflects the image light emitted from the lens system toward the object to be projected. Further, the concave reflecting surface reflects at least a part of the light rays contained in the image light incident on the concave reflecting surface in a direction intersecting the direction along the reference axis at an angle of 80 degrees or more.

In this image display device, the concave reflecting surface reflects at least a part of the image light in a direction that intersects a direction along a reference axis, which is a reference in forming a projection optical system, at an angle of 80 degrees or more. Will be done. This makes it possible to support the projection of an image on, for example, a curved screen, and it is possible to realize a high-quality image display.

The image light may include a plurality of pixel lights. In this case, the concave reflecting surface may reflect at least one pixel light out of the plurality of pixel lights in a direction intersecting the direction along the reference axis at an angle of 80 degrees or more.

The image display device sets the angle at which the traveling direction of each light ray included in the image light reflected by the concave reflecting surface intersects the direction along the reference axis as θ1, and the light ray having the largest angle θ1. If the angle θ1 of is θ1max,
It may be configured to satisfy the relationship of 80 degrees ≤ θ1 max ≤ 160 degrees.

The concave reflecting surface may be configured such that the axis of rotational symmetry coincides with the reference axis. In this case, the image display device obtains a derivative obtained by differentiating the ray height from the reference axis with h and the function Z (h) representing the shape of the concave reflecting surface according to the ray height with the ray height. Z'(h), the ray height corresponding to the reflection point farthest from the reference axis that reflects the image light is hmax, and the average value of Z'(h) from the reference axis to the ray height hmax is Z. 'ave. Then
1 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | <20
It may be configured to satisfy the relationship of.

The reference axis may be an axis extending the optical axis of the lens closest to the image generation unit included in the lens system.

The lens system may be configured such that the optical axis of each of the one or more optical components included in the lens system coincides with the reference axis.

The concave reflecting surface may be configured such that the optical axis of the concave reflecting surface coincides with the reference axis.

The concave reflecting surface may be a free curved surface having no axis of rotational symmetry.

The projection optical system according to one embodiment of the present technology is a projection optical system that projects image light generated by modulating light emitted from a light source, and includes the lens system and the concave reflecting surface. ..

An image display system according to an embodiment of the present technology includes an object to be projected and one or more image display devices.
Each of the one or more image display devices has the light source, the image generation unit, and the projection optical system.

The image generation unit may have an image modulation element that emits the image light. In this case, the image modulation element may have a plurality of pixels, each of which emits pixel light, and may emit the image light including a plurality of pixel lights emitted from the plurality of pixels.
Further, in the image display system, the optical path length of the pixel light emitted from the pixel closest to the reference axis of the image modulation element to the object to be projected is Lp1, and the pixel closest to the reference axis is the center of the image modulation element. Let Lp2 be the optical path length of the pixel light emitted from the pixel farthest from the reference axis to the object to be projected, which is located on the straight line connecting the pixels.
0.005 <Lp1 / Lp2 <0.5
It may be configured to satisfy the relationship of.

In the image display system, among the light rays included in the image light, the optical path length of the light ray having the shortest optical path length to the object to be projected is Ln, and the optical path length of the light ray having the longest optical path length is Lf.
0.005 <Ln / Lf <0.5
It may be configured to satisfy the relationship of.

The projectile may be a curved screen. In this case, the one or more image display devices may be installed so that the concave reflecting surface is arranged at a position corresponding to the shape of the curved screen.

The one or more image display devices may include a first image display device that projects a first image onto the curved screen, and a second image display device that projects a second image onto the curved screen. .. In this case, the first image display device and the second image display device display the first image and the second image, respectively, so that the first image and the second image overlap each other. It may be projected.

The first image display device and the second image display device are such that the image lights forming a region other than the region where the first image and the second image overlap each other do not intersect with each other. The first image and the second image may be projected, respectively.

The image generation unit may generate the image light that constitutes a rectangular image. In this case, the first image display device and the second image display device have the first image and the second image along the long side direction of the first image and the second image. The first image and the second image may be projected so as to overlap each other.

The image generation unit may generate the image light that constitutes a rectangular image. In this case, the first image display device and the second image display device have the first image and the second image along the short side direction of the first image and the second image. The first image and the second image may be projected so as to overlap each other.

The projectile may be a screen having a dome shape.

The one or more image display devices may include three or more image display devices.

As described above, according to the present technology, it is possible to support an ultra-wide angle and realize a high-quality image display. The effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a schematic diagram for demonstrating another advantage of an ultra-wide-angle compatible liquid crystal projector. It is the schematic which shows the structural example of the projection type image display device. It is a schematic diagram which shows the structural example of the image display system which concerns on 1st Embodiment. It is a schematic diagram which shows the structural example of the image display system which concerns on 1st Embodiment. It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on 1st Embodiment. It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on 1st Embodiment. It is a table which shows an example of the parameter about image projection. It is a schematic diagram for demonstrating the parameter shown in FIG. 7. It is the lens data of the image display device and the data of the curved screen. It is a table which shows an example of the aspherical coefficient of an optical component included in a projection optical system. It is a table which shows Z (h) and Z'(h) at a ray height h. It is a graph which shows the relationship between the light ray height h and "thita". It is a graph which shows the relationship between the light ray height h and "Δθ". It is a table which shows the numerical value of the parameter used in the conditional expression (2)-(4). It is a schematic diagram for demonstrating the projection of an image on a curved screen by an image display device given as a comparative example. It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on 2nd Embodiment. It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on 2nd Embodiment. It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on 2nd Embodiment. It is a table which shows an example of the parameter about image projection. It is the lens data of the image display device and the data of the curved screen. It is a table which shows an example of the aspherical coefficient of an optical component included in a projection optical system. It is a table which shows Z (h) and Z'(h) at a ray height h. It is a graph which shows the relationship between the light ray height h and "thita". It is a graph which shows the relationship between the light ray height h and "Δθ". It is a table which shows the numerical value of the parameter used in the conditional expression (2)-(4). It is an optical path diagram which shows the schematic structure example of the projection optical system which concerns on other embodiment. It is a schematic diagram which shows the structural example of the image display system which concerns on other embodiment. It is a schematic diagram which shows the structural example of the image display system which concerns on other embodiment.

Hereinafter, embodiments relating to the present technology will be described with reference to the drawings.

[Overview of projection type image display device]
The outline of the projection type image display device will be briefly described by taking a liquid crystal projector as an example. The liquid crystal projector spatially modulates the light emitted from the light source to form an optical image (image light) corresponding to the video signal. A liquid crystal display element or the like, which is an image modulation element, is used for light modulation. For example, a three-panel liquid crystal projector equipped with a panel-shaped liquid crystal display element (liquid crystal panel) corresponding to each of RGB is used.

The optical image is magnified and projected by the projection optical system and displayed on the screen. Here, it is assumed that the projection optical system corresponds to, for example, an ultra-wide angle in which the half angle of view is in the vicinity of 70 °. Of course, it is not limited to this angle.

A liquid crystal projector that supports an ultra-wide angle can display a large screen even in a small projection space. That is, magnified projection is possible even when the distance between the liquid crystal projector and the screen is short. As a result, the following advantages are exhibited.

Since the liquid crystal projector can be arranged close to the screen, it is possible to sufficiently suppress the possibility that the light from the liquid crystal projector directly enters the human eye, and high safety is exhibited.
Efficient presentations are possible because shadows of humans and the like do not appear on the screen.
It has a high degree of freedom in selecting the installation location, and can be easily installed even in a narrow installation space or a ceiling with many obstacles.
By installing it on the wall, maintenance such as cable routing is easier than when installing it on the ceiling.
For example, it is possible to increase the degree of freedom in setting the meeting space, classroom, conference room, and the like.

FIG. 1 is a schematic diagram for explaining other advantages of an ultra-wide-angle compatible liquid crystal projector. As shown in FIG. 1, by installing the ultra-wide-angle compatible liquid crystal projector 1 on the table, it is possible to project the enlarged image 2 on the same table. This kind of usage is also possible, and the space can be used efficiently.

Recently, with the spread of electronic blackboards (Interactive White Boards) in schools and workplaces, the demand for ultra-wide-angle LCD projectors is increasing. Similar liquid crystal projectors are also used in fields such as digital signage (electronic advertising). As the electronic blackboard, for example, technologies such as LCD (Liquid Crystal Display) and PDP (Plasma Display Panel) can be used. Compared to these, by using an ultra-wide-angle compatible liquid crystal projector, it is possible to reduce costs and provide a large screen. An ultra-wide-angle LCD projector is also called a short-focus projector or an ultra-short throw projector.

FIG. 2 is a schematic view showing a configuration example of a projection type image display device. The image display device 20 includes a light source 5, an illumination optical system 10, and a projection optical system 15.

The light source 5 is arranged so as to emit a luminous flux with respect to the illumination optical system 10. As the light source 5, for example, a high-pressure mercury lamp or the like is used. In addition, a solid-state light source such as an LED (Light Emitting Diode) or an LD (Laser Diode) may be used.

The illumination optical system 10 uniformly irradiates the light beam emitted from the light source 5 onto the surface of the image modulation element (liquid crystal panel P) which is the primary image plane. In the illumination optical system 10, the luminous flux from the light source 5 passes through the two fly-eye lens FL, the polarization conversion element PS, and the condensing lens L in order, and is converted into a uniform luminous flux with uniform polarization.

The luminous flux that has passed through the condenser lens L is separated into RGB color component light by a dichroic mirror DM that reflects only light in a specific wavelength band. Each color component light of RGB is incident on a liquid crystal panel P (image modulation element) provided corresponding to each color of RGB through a total reflection mirror M, a lens L, or the like. Then, each liquid crystal panel P performs optical modulation according to the video signal. The light-modulated color component lights are combined by the dichroic prism PP to generate image light. Then, the generated image light is emitted toward the projection optical system 15.

The optical components and the like constituting the illumination optical system 10 are not limited, and optical components different from the optical components described above may be used. For example, as the image modulation element, a reflective liquid crystal panel, a digital micromirror device (DMD), or the like may be used instead of the transmissive liquid crystal panel P. Further, for example, instead of the dichroic prism PP, a polarization beam splitter (PBS), a color synthesis prism for synthesizing video signals of each RGB color, a TIR (Total Internal Reflection) prism, or the like may be used. In the present embodiment, the illumination optical system 10 corresponds to an image generation unit.

The projection optical system 15 adjusts the image light emitted from the illumination optical system 10 and performs magnified projection on a screen serving as a secondary image plane. That is, the image information of the primary image plane (liquid crystal panel P) is adjusted by the projection optical system 15, and the image information is magnified and projected onto the secondary image plane (screen).

<First Embodiment>
[Image display system]
3 and 4 are schematic views showing a configuration example of an image display system according to the first embodiment of the present technology. FIG. 3 is a view of the image display system 100 as viewed from above. FIG. 4 is a view of the image display system 100 viewed obliquely from above on the right front side.

The image display system 100 includes a curved screen 30 and two image display devices 20. The curved screen 30 includes both a screen having a curved shape as a whole and a screen having a curved shape at least a part of the shape.

As shown in FIGS. 3 and 4, in this embodiment, a curved screen 30 having a substantially arc shape when viewed from above is used. The curved screen 30 is erected along the vertical direction and is installed so as to extend in the horizontal direction. The left and right ends 31a and 31b of the curved screen 30 are bent forward and arranged at substantially equal positions in the front-rear direction. The substantially central portion of the curved screen 30 in the left-right direction is located at the rearmost side and corresponds to the apex of the substantially arc shape seen from above.

It is also possible to express that the shape of the curved screen 30 is substantially equal to a part of the inner surface of a cylinder erected along the vertical direction. Further, the curved screen 30 may be formed by connecting minute plane regions while changing their angles.

The specific configuration of the curved screen 30, such as the material, size, and radius of curvature, is not limited and may be arbitrarily designed. Further, the curved screen 30 may be realized by adhering a flexible screen member to the inner surface of the base portion having an arc shape when viewed from above. In this embodiment, the curved screen 30 corresponds to an object to be projected.

The two image display devices 20 include a first image display device 20a and a second image display device 20b. The first image display device 20a is installed so as to be able to project an image rearward at a substantially central portion in the vertical direction of the left end portion 31a of the curved screen 30. The first image display device 20a projects an image (hereinafter referred to as a first image) 21a on a region on the left side of a curved screen 30 bent in a substantially arc shape.

The second image display device 20b is installed so as to be able to project an image rearward at a substantially central portion in the vertical direction of the right end portion 31b of the curved screen 30. The second image display device 20b projects an image (hereinafter referred to as a second image) 21b onto a region on the right side of the curved screen 30 bent in a substantially arc shape. The holding mechanism (not shown) for holding the first and second image display devices 20a and 20b may be arbitrarily designed.

As shown in FIGS. 3 and 4, the first and second image display devices 20a and 20b have the first and second images 21a and 20b so that the first and second images 21a and 21b overlap each other. 21b are projected respectively.

In the present embodiment, the image modulation element (liquid crystal panel P) provided in the first and second image display devices 20a and 20b has a rectangular shape having a long side direction and a short side direction. Then, the liquid crystal panel P generates image light that constitutes a rectangular image.

The first and second images 21a and 21b are projected as rectangular images equal to each other, respectively. Then, the first and second images 21a and 21b are projected along the long side direction (horizontal direction) of the first and second images 21a and 21b so as to overlap each other, respectively. Therefore, an overlapping region 22 in which the first and second images 21a and 21b overlap each other is generated in the substantially central portion of the curved screen 30.

In the present embodiment, the stitching process is executed in the overlapping region 22 where the first and second images 21a and 21b overlap. As a result, the first and second images 21a and 21b are connected and combined as one image. As a result, one large-sized image is displayed in a substantially entire area along the left-right direction of the curved screen 30. The specific algorithm of the stitching process is not limited, and any stitching technique may be used.

In FIG. 3, the first image light 23a constituting the first image 21a projected from the first image display device 20a and the pixel lights Ca1, Ca2, and Ca3 included in the first image light 23a are schematically shown. Is illustrated in.

Further, in FIG. 3, the first image light 23b constituting the second image 21b projected from the second image display device 20b and the pixel lights Cb1, Cb2, and Cb3 included in the second image light 23b are schematic. Is illustrated.

The pixel light is light for forming each of a plurality of pixels included in the projected image. Typically, the light emitted from each of the plurality of pixels included in the image modulation element (liquid crystal panel P) that generates and emits image light becomes the pixel light. Therefore, the image light includes a plurality of pixel lights.

The pixel light Ca1 shown in FIG. 3 is pixel light for forming the pixels at the left end of the first image 21a. Therefore, the pixel light Ca1 corresponds to the light beam at the left end of the first image light 23a. The pixel light Ca2 is pixel light for forming the pixel at the right end of the first image 21a. Therefore, the pixel light Ca2 corresponds to the light beam at the right end of the first image light 23a.

The pixel light Ca3 is pixel light for forming the pixel at the left end of the overlapping region 22 where the first and second images 21a and 21b overlap. Therefore, among the light rays included in the first image light 23a, the light rays from the pixel lights Ca3 to Ca2 are the image lights forming the overlapping region 22. On the other hand, among the light rays included in the first image light 23a, the light rays from the pixel lights Ca1 to Ca3 are image lights constituting a region other than the overlapping region 22.

The pixel light Cb1 shown in FIG. 3 is pixel light for forming the pixel at the right end of the second image 21b. Therefore, the pixel light Cb1 corresponds to the light beam at the right end of the second image light 23b. The pixel light Cb2 is pixel light for forming the pixel at the left end of the second image 21b. Therefore, the pixel light Cb2 corresponds to the light beam at the left end of the first image light 23a.

The pixel light Ca3 is pixel light for forming the pixel at the right end of the overlapping region 22. Therefore, among the light rays included in the second image light 23b, the light rays from the pixel lights Cb3 to Cb2 are the image lights forming the overlapping region 22. On the other hand, among the light rays included in the second image light 23b, the light rays from the pixel lights Cb1 to Cb3 are image lights forming a region other than the overlapping region 22.

As shown in FIG. 3, in the present embodiment, the first and second image display devices 20a and 20b form an image other than the overlapping area 22 in which the first and second images 21a and 21b overlap each other. The first and second images 21a and 21b are projected, respectively, so that the lights do not intersect each other.

As a result, it is possible to sufficiently suppress the shadow of the user 3 standing at a position close to the overlapping region 22 generated in the substantially central portion of the curved screen 30. As a result, the user 3 views the first and second images 21a and 21b combined into one image from the inner region (for example, a position close to the overlapping region 22) of the curved screen 30 bent into an arc shape. It becomes possible. As a result, it is possible to realize a very high immersive feeling in the content, and it is possible to provide the user 3 with an excellent visual effect.

The direction in which the first and second images 21a and 21b overlap is not limited. For example, the first and second images 21a and 21b may be projected along the short side direction of the first and second images 21a and 21b so as to overlap each other. For example, in the configuration examples shown in FIGS. 3 and 4, rectangular first and second images 21a and 21b having the left-right direction as the short side direction are projected. Then, even if the first and second images 21a and 21b are projected so that the first and second images 21a and 21b overlap along the short side direction of the first and second images 21a and 21b. Good.

Depending on the shape of the curved screen 30, when the image light constituting the rectangular image is projected, the image may be displayed in a shape different from the rectangular shape. In this case, for example, the directions corresponding to the long side direction and the short side direction of the liquid crystal panel P can be defined as the long side direction and the short side direction of the image. Then, it is possible to overlap a plurality of images along the long side direction or the short side direction. In the present disclosure, the long side direction and the short side direction of the liquid crystal panel P may be expressed as the long side direction and the short side direction of the image light.

A detailed configuration example of the first and second image display devices 20a and 20b and the curved screen 30 will be described. In the present embodiment, as the first and second image display devices 20a and 20b, image display devices having substantially the same configuration as each other are used. Hereinafter, the projection optical system 15 of the first and second image display devices 20a and 20b and the curved screen 30 will be described.

5 and 6 are optical path diagrams showing a schematic configuration example of the projection optical system 15 according to the present embodiment. Note that FIG. 6 shows one projection optical system 15 and a portion on which the image of the curved screen S is projected. By combining two configurations of FIG. 6 so as to be symmetrical to each other, an image display system 100 having a curved screen 30 and first and second image display devices 20a and 20b shown in FIGS. 3 and 4 can be obtained. It is possible to achieve it.

Further, in FIGS. 5 and 6, the liquid crystal panel P and the dichroic prism PP of the illumination optical system 10 are schematically illustrated. Hereinafter, the emission direction of the image light emitted from the dichroic prism PP to the projection optical system 15 is defined as the Z direction. Further, the horizontal direction of the primary image plane (liquid crystal panel P) is the X direction, and the vertical direction is the Y direction. The X and Y directions correspond to the horizontal and vertical directions of the image composed of the image light.

The projection optical system 15 includes a first optical system L1 and a second optical system L2. The first optical system L1 is configured at a position where the image light generated by the illumination optical system 10 is incident, and has a positive refractive power as a whole. Further, the first optical system L1 is configured with reference to a reference axis extending in the Z direction (hereinafter, this reference axis is referred to as an optical axis O).

As shown in FIG. 5, in the present embodiment, in the first optical system L1, each optical axis of one or more optical components included in the first optical system L1 is abbreviated as an optical axis O which is a reference axis. Configured to match. The optical axis of the optical component is typically an axis that passes through the center of the optical surface such as the lens surface or the reflective surface of the optical component. For example, when the optical surface of an optical component has a rotation symmetry axis, the rotation symmetry axis corresponds to the optical axis.

In the present embodiment, the optical axis O is an extension of the optical axis (rotational symmetry axis) of the lens L11 closest to the illumination optical system 10 included in the first optical system L1. That is, other optical components are arranged on the axis extending the optical axis of the lens L11. The image light is emitted along the optical axis O from a position offset in the vertical direction (Y direction) from the optical axis O. In the present embodiment, the first optical system L1 corresponds to a lens system. Further, the direction along the optical axis O can be referred to as the optical path traveling direction of the first optical system L1.

As shown in FIG. 5, the first optical system L1 has a first reflecting surface Mr1 and a second reflecting surface Mr2. The first and second reflecting surfaces Mr1 and Mr2 are concave reflecting surfaces. The first reflecting surface Mr1 is a rotationally symmetric spherical surface configured so that the axis of rotational symmetry coincides with the optical axis O.

The second reflecting surface Mr2 is a rotationally symmetric aspherical surface configured so that the axis of rotational symmetry coincides with the optical axis O, and is composed of only a portion capable of reflecting an effective region which is a region where image light is incident. There is. That is, instead of arranging the entire rotationally symmetric aspherical surface, only the necessary parts of the rotationally symmetric aspherical surface are arranged. This makes it possible to reduce the size of the device.

The second optical system L2 is composed of a concave reflecting surface Mr3. The concave reflecting surface Mr3 is configured with reference to the optical axis O, which is a reference axis, and reflects the image light emitted from the first optical system L1 toward the curved screen S (curved screen 30).

The concave reflecting surface Mr3 is a rotationally symmetric aspherical surface configured so that the rotational symmetry axis (optical axis) coincides with the optical axis O, and the effective region, which is the region where the image light is incident, is composed of only the reflective portion. Has been done. That is, instead of arranging the entire rotationally symmetric aspherical surface, only the necessary parts of the rotationally symmetric aspherical surface are arranged. This makes it possible to reduce the size of the device.

As shown in FIG. 5, in the present embodiment, the first optical system L1 and the second optical system L2 (concave reflection surface Mr3) are configured on the common optical axis O. That is, the first and second optical systems L1 and so that the axis extending the optical axis (rotational symmetry axis) of the lens L11 closest to the illumination optical system 10 substantially coincides with each optical axis (rotational symmetry axis). L2 is configured. As a result, the size in the Y direction can be reduced, and the device can be miniaturized.

The optical path of the image light will be described with reference to FIGS. 5 and 6. FIG. 5 shows the optical paths of four pixel lights C1, C2, C3, and C4 among the image lights emitted from the dichroic prism PP to the projection optical system 15. In FIG. 6, the optical paths of the three pixel lights C1, C2, and C3 are shown.

As will be described later with reference to FIG. 8, the pixel light C1 corresponds to the pixel light emitted from the central pixel of the liquid crystal panel P. The pixel light C2 corresponds to the pixel light emitted from the pixel closest to the optical axis O in the center of the liquid crystal panel P. It corresponds to the pixel light emitted from the pixel farthest from the optical axis O in the center of the liquid crystal panel P. The pixel light C4 corresponds to the pixel light emitted from the pixel at the upper right end of the liquid crystal panel P.

That is, in the present embodiment, the pixel light C2 corresponds to the pixel light emitted from the pixel closest to the optical axis O of the liquid crystal panel P. Further, the pixel light C3 is located on a straight line connecting the pixel closest to the optical axis O to the central pixel of the liquid crystal panel P, and corresponds to the pixel light emitted from the pixel farthest from the optical axis O.

The image light emitted from the position vertically offset from the optical axis O to the projection optical system 15 along the optical axis O travels intersecting the optical axis O and is incident on the first reflection surface Mr1. The image light incident on the first reflecting surface Mr1 is folded back by the first reflecting surface Mr1 and travels again intersecting the optical axis O, and is incident on the second reflecting surface Mr2.

The image light incident on the second reflecting surface Mr2 is folded back by the second reflecting surface Mr2 and emitted from the first optical system L1. The image light is emitted toward the concave reflecting surface Mr3 so as to intersect the optical axis O again. The image light emitted from the first optical system L1 is reflected by the concave reflecting surface Mr3 which is the second optical system L2, intersects the optical axis O again, and is projected toward the curved screen S.

As described above, in the present embodiment, the optical path of the image light is configured so as to intersect the optical axis O. As a result, the optical path of the image light up to the concave reflection surface Mr3 can be configured in the vicinity of the optical axis O. As a result, the size of the device in the Y direction can be reduced, and the device can be miniaturized.

Further, the image light is folded back and reflected by each of the first and second reflecting surfaces Mr1 and Mr2. This makes it possible to secure a sufficient optical path length of the image light. As a result, the size of the device in the X direction can be reduced, and the device can be miniaturized.

As shown in FIGS. 5 and 6, in the present embodiment, due to the concave reflecting surface Mr3, at least a part of the light rays included in the image light incident on the concave reflecting surface Mr3 is along the optical axis O which is the reference axis. It is reflected in the direction that intersects the direction at an angle of 80 degrees or more.

The crossing angle between the traveling direction of the light rays included in the image light reflected by the concave reflecting surface Mr3 and the direction along the optical axis O is defined as follows. First, the intersection of the straight line extending along the optical axis O and the straight line extending along the traveling direction of the light ray reflected by the concave reflecting surface Mr3 is calculated. A straight line extending from the intersection to the liquid crystal panel P side is rotated in the traveling direction side of the light beam with the intersection as a reference. At that time, the rotation angle until the straight line extending from the intersection to the liquid crystal panel P side coincides with the straight line extending along the traveling direction of the light ray is the light ray included in the image light reflected by the concave reflecting surface Mr3. Is defined as the angle of intersection between the traveling direction of the light beam and the direction along the optical axis O.

In the present embodiment, the concave reflecting surface Mr3 is designed so that the crossing angle of at least a part of the light rays contained in the image light reflected by the concave reflecting surface Mr3 is 80 degrees or more as defined above.

In the example shown in FIG. 5, the pixel light C4 included in the image light is reflected in a direction that intersects the direction along the optical axis O at an angle of 80 degrees or more. As shown in FIG. 5, the crossing angle between the traveling direction of the pixel light C4 reflected by the concave reflecting surface Mr3 and the direction along the optical axis O is an angle R1. This angle R1 is 87.4 degrees.

This angle R1 is the maximum crossing angle. That is, the pixel light C4 is a light ray having the largest crossing angle. The other light rays are reflected in a direction that intersects the direction along the optical axis O at an angle smaller than the angle R1 (87.4 degrees).

Here, pixel light is taken as an example of light rays included in the image light. Not limited to this, at least a part of the light rays such as a part of the light rays included in the pixel light may be reflected in the direction intersecting the direction along the optical axis O at an angle of 80 degrees or more.

The image display device 20 including the projection optical system 15 as illustrated in FIGS. 5 and 6 is installed so that the concave reflection surface Mr3 is arranged at a position corresponding to the shape of the curved screen S. By designing the concave reflecting surface Mr3 so that the crossing angle becomes large, it is possible to realize a high-quality image display corresponding to the curved screen S. This point will be described in detail later.

Here, the present inventor has found four conditions (1) to (4) regarding image display corresponding to a curved screen. These conditions will be described with reference to FIGS. 5 and 6.

(Condition 1)
Let θ1 be the angle at which the traveling direction of each light ray included in the image light reflected by the concave reflecting surface Mr3 intersects with the direction along the optical axis O, which is the reference axis. The angle θ1 corresponds to the intersection angle defined above.
Let θ1max be the angle θ1 of the light ray having the largest angle θ1. In the example shown in FIG. 5, the intersection angle of the pixel light C4 is θ1max.
In this case, the projection optical system 15 is configured so as to satisfy the following relationship. (1) 80 degrees ≤ θ1max ≤ 160 degrees

This conditional expression (1) regulates an appropriate reflection angle of light rays contained in image light. When θ1max is less than the lower limit defined in the conditional expression (1), the light rays are not reflected at a large angle, and it becomes difficult to correspond to the curved screen S. When θ1max exceeds the upper limit specified in the conditional expression (1), there is a high possibility that the light beam interferes with the concave reflection surface Mr3 itself. That is, after being reflected by the concave reflecting surface Mr3, there is a high possibility that it will be incident on another portion of the concave reflecting surface Mr3 again.

The crossing angle of the pixel light C4 is 87.4 degrees, and it can be seen that the condition 1 is satisfied.

(Condition 2)
The concave reflecting surface Mr3 is configured so that the axis of rotational symmetry coincides with the optical axis O which is the reference axis.
Let h be the height of the light incident on the concave reflecting surface Mr3 from the optical axis O.
Let Z'(h) (= dZ / dh) be a derivative obtained by differentiating the function Z (h) representing the shape of the concave reflecting surface Mr3 according to the ray height by the ray height. Therefore, the derivative Z'(h) corresponds to the slope of a straight line tangent to the concave reflecting surface Mr3 at the ray height h.
Let hmax be the height of the light beam corresponding to the reflection point farthest from the optical axis O that reflects the image light.
The average value of Z'(h) from the optical axis O to the ray height hmax is defined as Z'ave. And.
In this case, the projection optical system 15 is configured so as to satisfy the following relationship. (2) 1 <<Z'(1.0 · hmax) −Z'(0.9 · hmax) | / | Z'ave . ｜ ＜ 20

This conditional expression (2) regulates an appropriate reflection angle of light rays contained in the image light. When | Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | Does not meet the lower limit specified in the conditional expression (2), the light beam is reflected at a large angle. Without doing so, it becomes difficult to correspond to the curved screen S. When | Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | Exceeds the upper limit specified in the conditional expression (2), the light beam is the concave reflecting surface Mr3. There is a high possibility that it will interfere with itself. That is, after being reflected by the concave reflecting surface Mr3, there is a high possibility that it will be incident on another portion of the concave reflecting surface Mr3 again.

(Condition 3)
The optical path length of the pixel light emitted from the pixel closest to the optical axis O of the liquid crystal panel P to the curved screen S is Lp1, and the pixel closest to the optical axis O is located on a straight line connecting the central pixel of the liquid crystal panel P. Let Lp2 be the optical path length of the pixel light emitted from the pixel farthest from the optical axis O to the curved screen S. In the present embodiment, the optical path length of the pixel light C2 is Lp1, and the optical path length of the pixel light C3 is Lp2.
In this case, the projection optical system 15 and the curved screen S are configured so as to satisfy the following relationship.
(3) 0.005 <Lp1 / Lp2 <0.5

This conditional expression (3) corresponds to the conditional expression for defining the movable area of the user 3 illustrated in FIG. When Lp1 / Lp2 does not meet the lower limit defined in the conditional expression (3), the generation of shadows can be suppressed even when the user 3 stands near the screen S, and the movable area of the user 3 is increased. Can be taken. On the other hand, there is a high possibility that the optical path length difference becomes too large and the optical performance is reduced. When Lp1 / Lp2 exceeds the upper limit defined in the conditional expression (3), if the user 3 does not move away from the screen S, the light beam interferes with the user 3 and a shadow of the user 3 is generated. Further, it is necessary to keep the projection optical system 15 away from the curved screen S, which increases the size of the entire device.

(Condition 4)
Among the light rays included in the image light, the optical path length of the light ray having the shortest optical path length to the curved screen S is Ln, and the optical path length of the light ray having the longest optical path length is Lf. In the example shown in FIG. 6, the optical path length of the pixel light C2 is Ln, and the optical path length of the pixel light C3 is Lf.
In this case, the projection optical system 15 and the curved screen S are configured so as to satisfy the following relationship.
(4) 0.005 <Ln / Lf <0.5

Similar to the conditional expression (3), this conditional expression (4) also corresponds to the conditional expression for defining the movable area of the user 3 illustrated in FIG. That is, when Ln / Lf is less than the lower limit defined in the conditional expression (4), the generation of shadows can be suppressed even when the user 3 stands near the screen S, and the movable area of the user 3 can be suppressed. It can be taken large. On the other hand, there is a high possibility that the optical path length difference becomes too large and the optical performance is reduced. When Ln / Lf exceeds the upper limit defined in the conditional expression (4), if the user 3 does not move away from the screen S, the light beam interferes with the user 3 and a shadow of the user 3 is generated. Further, it is necessary to keep the projection optical system 15 away from the curved screen S, which increases the size of the entire device.

The lower limit value and the upper limit value of each of the conditional expressions (1) to (4) are not limited to the above-mentioned values. For example, each value can be appropriately changed according to the configuration of the illumination optical system 10, the projection optical system 15, the curved screen S, and the like. For example, any value included in the above range may be selected as the lower limit value and the upper limit value, and may be set again as the optimum range.

For example, the conditional expression (1) can be set in the following range.
85 degrees ≤ θ1max ≤ 160 degrees 80 degrees ≤ θ1max ≤ 140 degrees 85 degrees ≤ θ1max ≤ 140 degrees

For example, the conditional expression (2) can be set in the following range.
1 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | <10
2 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | <10

The projection optical system 15 configured as described above will be briefly described with specific numerical examples.

FIG. 7 is a table showing an example of parameters related to image projection. FIG. 8 is a schematic diagram for explaining the parameters shown in FIG. 7.

The numerical aperture NA of the projection optical system 15 on the primary image plane side is 0.127. The horizontal and vertical lengths (H × VSp) of the image modulation element (liquid crystal panel P) are 8.2 mm and 4.6 mm. The center position (Chp) of the image modulation element is 3.7 mm above the optical axis O. The image circle (imc) on the primary image plane side is φ14.6 mm.

As described above, the light emitted from the central pixel of the liquid crystal panel P shown in FIG. 8 corresponds to the pixel light C1 shown in FIG. 5 and the like (the same reference numerals are given). The light emitted from the pixel closest to the optical axis O in the center of the liquid crystal panel P corresponds to the pixel light C2 (with the same reference numerals). The light emitted from the pixel farthest from the optical axis O in the center of the liquid crystal panel P corresponds to the pixel light C3 (with the same reference numerals).

The light emitted from the upper right pixel of the liquid crystal panel P corresponds to the pixel light C4 shown in FIG. 5 and the like (the same reference numerals are given). In the present embodiment, the pixel light C4 emitted from the pixel is reflected by the concave reflecting surface Mr3 in a direction that intersects the direction along the optical axis O at an angle of 80 degrees or more.

FIG. 9 shows the lens data of the image display device and the data of the curved screen. FIG. 9 shows data on 1 to 24 optical components (lens surfaces) arranged from the primary image plane (P) side to the secondary image plane (S) side, and the curved screen S. There is. As the data of each optical component (lens surface), the radius of curvature (mm), the core thickness d (mm), the refractive index nd at the d line (587.56 nm), and the Abbe number νd at the d line are described. Has been done. For the curved screen S, the radius of curvature (mm) is described.

The optical component having an aspherical surface follows the following formula.

FIG. 10 is a table showing an example of the aspherical coefficient of the optical component included in the projection optical system. FIG. 10 shows the aspherical coefficients for each of the aspherical optical components marked with * in FIG. 9, 12, 13, 15 and 24, respectively. The aspherical coefficient in the example corresponds to the above equation (Equation 1).

In this embodiment, the equation (Equation 1) corresponds to the function Z (h) representing the shape of the concave reflecting surface Mr3 according to the height of the light beam. When the ray height h shown in FIG. 5 is input to the equation (Equation 1), the sag amount Z is used as a parameter representing the shape of the concave reflecting surface Mr3 according to the ray height. The "sag amount" is the distance between the plane and the point on the lens surface in the optical axis direction when a plane perpendicular to the optical axis is erected through the surface apex.

Therefore, the derivative Z'(h) (= dZ / dh) obtained by differentiating the function Z (h) with respect to the ray height has the following equation.

As described above, the slope of the straight line in contact with the concave reflecting surface Mr3 at the ray height h is calculated by this equation.

The curved screen S is eccentric and tilted with respect to the optical axis O. FIG. 10 shows an eccentric component of the curved screen S in the XYZ direction and a rotation component around each axis of the XYZ.

The XDE, YDE, and ZDE illustrated in FIG. 10 indicate the X-direction component (unit: mm), the Y-direction component (unit: mm), and the Z-direction component (unit: mm) of the eccentricity of the surface. ADE, BDE, and CDE are the θx direction component of surface rotation (rotation component around the X axis; unit: degree), the θy direction component (rotation component around the Y axis; unit: degree), and the θz direction component (Z). The rotation component around the axis; unit: degree) is shown.

FIG. 11 is a table showing Z (h) and Z'(h) at the ray height h. In FIG. 11, the sag amount of Z (h) is described as “shape” (unit: mm). Further, the slope of the tangent line which is Z'(h) is described as "thita". Further, in FIG. 11, the displacement amount of the inclination of the tangent line according to the displacement of the ray height h is shown as “Δθ”. The ray height of the optical axis O is set to 0, the ray height hmax is set to 1, and the calculation is performed after normalizing the ray height h.

FIG. 12 is a graph showing the relationship between the ray height h and “thita”. FIG. 13 is a graph showing the relationship between the ray height h and “Δθ”. It can be seen that the slope of the tangent line changes significantly from the height of the light beam 0.9 to 1.00 away from the optical axis O. This means that the curvature increases from 0.9 to 1.00 the height of the light beam. This makes it possible to increase the intersection angle θ1.

FIG. 14 is a table showing the numerical values of the parameters used in the above conditional expressions (2) to (4) in the present embodiment.
| Z'(1.0 · hmax) -Z'(0.9 · hmax) | 11.8
｜ Z'ave. ｜ 5.7
| Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | 2.07
Optical path length of C1 1031.11 mm
Optical path length of C2 (= Lp1 = Ln) 634.76 mm
Optical path length of C3 (= Lp2 = Lf) 1311.61 mm
Optical path length of C4 1236.61 mm
Lp1 / Lp2 0.48
Ln / Lf 0.48
As a result, it can be seen that the conditional expressions (2) to (4) are satisfied.

As described above, in the image display system 100 according to the present embodiment, the concave reflection surface Mr3 allows at least a part of the light rays of the image light to be directed along the optical axis O, which is a reference in forming the projection optical system 15, and 80. It is reflected in the direction of intersection at an angle of more than a degree. As a result, for example, it is possible to support the projection of an image on a curved screen S or the like, and it is possible to realize a high-quality image display.

FIG. 15 is a schematic diagram for explaining the projection of an image onto a curved screen by an image display device given as a comparative example.

The image display device 90 is a projector compatible with an ultra-wide angle, and the configuration of the concave reflecting surface that reflects the image light on the curved screen is different from that of the image display device 20 according to the present embodiment. Specifically, the concave reflecting surface reflects all the light rays contained in the image light in a direction intersecting the optical axis, which is a reference in forming the projection optical system, at an angle of less than 80 degrees.

Consider a case where an image is projected on the curved screen S with the maximum size by such an image display device 90. For example, as shown in FIG. 15A, it is assumed that the image 92 is projected on the curved screen S in the same manner as when the image 91 is projected on the flat screen S'. That is, consider the case where the same image light is projected onto the flat screen S'and the curved screen S, respectively.

Then, as a matter of course, the image 91 displayed on the flat screen S'and the image 92 displayed on the curved screen S have different shapes. Considering the image 91 displayed on the flat screen S'as a reference, the image 92 displayed on the curved screen S becomes a very distorted image.

Therefore, in order to properly display the image 92 on the curved screen S, it is necessary to perform an electrical correction process on the image signal. The amount of correction depends on the shape of the curved screen S, but is often very large. As a result, the image quality of the image 92 is deteriorated.

Further, as shown in FIG. 12B, in order to display the image 92 in a wide range of the curved screen S, the image display device 90 must be installed at a position away from the curved screen S. As a result, the presence of the image display device 90 becomes conspicuous for the user who views the image 92, and the immersive feeling in the content is impaired. In addition, since the area where the shadow of the user appears becomes large, the area where the user can move becomes small. As a result, it becomes difficult to provide an excellent viewing environment.

In the image display system 100 according to the present embodiment, the range that can be reflected by the concave reflecting surface Mr3 is designed to be as wide as 80 degrees or more with respect to the reference optical axis O. As a result, it is possible to suppress distortion of the image optically displayed on the surface screen S. As a result, it is possible to sufficiently suppress the amount of electrical correction for the image signal. As a result, it is possible to display an image with high image quality.

Further, as shown in FIG. 3, since it is possible to project an image over a wide range of the curved screen S from a position close to the curved screen S, the presence of the first and second image display devices 20a and 20b makes it possible to project the image. , It is possible to sufficiently suppress the hindrance of the user 3 to the content. Further, since the area where the shadow of the user 3 appears can be reduced, the area where the user 3 can move can be increased. As a result, it is possible to provide a very excellent viewing environment.

By replacing the concave reflective surface of the image display device 90 given as a comparative example with the concave reflective surface according to the present technology and optimizing the overall configuration of the first optical system, the image display device according to the present technology can be used. , It is also possible to realize it easily.

<Second embodiment>
The image display system of the second embodiment according to the present technology will be described. In the following description, the description of the same parts as those of the configuration and operation of the image display system 100 and the image display device 20 described in the above embodiment will be omitted or simplified.

16 to 18 are optical path diagrams showing a schematic configuration example of the projection optical system 215 according to the present embodiment. Note that in FIGS. 17 and 18, the configurations of the curved screen S are different from each other. Hereinafter, the configuration example shown in FIG. 17 may be described as Example 2-1 and the configuration example shown in FIG. 18 may be described as Example 2-2.

As shown in FIGS. 16 to 18, at least a part of the light rays contained in the image light incident on the concave reflecting surface Mr3 due to the concave reflecting surface Mr3 is 80 degrees or more with the direction along the optical axis O which is the reference axis. It is reflected in the direction of intersection at the angle of.

In the example shown in FIG. 16, the pixel light C4 included in the image light is reflected in a direction that intersects the direction along the optical axis O at an angle of 80 degrees or more. The intersection angle R1 of 128.2 degrees between the traveling direction of the pixel light C4 reflected by the concave reflecting surface Mr3 and the direction along the optical axis O is set. Further, it can be seen that this angle R1 is the maximum crossing angle and satisfies the conditional expression (1).

In the present embodiment, the pixel light C3 is also reflected in a direction that intersects the direction along the optical axis O at an angle of 80 degrees or more. The crossing angle of the pixel light C3 is 122.5 degrees.

FIG. 19 is a table showing an example of parameters related to image projection.
FIG. 20 shows lens data of an image display device and data of a curved screen.
FIG. 21 is a table showing an example of the aspherical coefficient of the optical component included in the projection optical system. Further, FIG. 21 shows an eccentric component in the XYZ direction and a rotation component around each axis of XYZ of the curved screen of Example 2-1 and the curved screen of Example 2-2.

FIG. 22 is a table showing Z (h) and Z'(h) at the ray height h.
FIG. 23 is a graph showing the relationship between the ray height h and “thita”.
FIG. 24 is a graph showing the relationship between the ray height h and “Δθ”.

FIG. 25 is a table showing the numerical values of the parameters used in the above conditional expressions (2) to (4) in the present embodiment.
| Z'(1.0 · hmax) -Z'(0.9 · hmax) | 13.7
｜ Z'ave. ｜ 7.8
| Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | 1.75
(Example 2-1)
Optical path length of C1 933.01 mm
Optical path length of C2 (= Lp1 = Ln) 418.12 mm
Optical path length of C3 (= Lp2) 1195.5 mm
Optical path length of C4 (= Lf) 1277.93 mm
Lp1 / Lp2 0.35
Ln / Lf 0.33
(Example 2-2)
Optical path length of C1 1045.3 mm
Optical path length of C2 (= Lp1 = Ln) 306.5 mm
Optical path length of C3 (= Lp2) 1319.84 mm
Optical path length of C4 (= Lf) 1329.16 mm
Lp1 / Lp2 0.23
Ln / Lf 0.23
As a result, it can be seen that the conditional expressions (2) to (4) are satisfied. In Examples 2-1 and 2-2, the optical path length of the pixel light C4 is Lf.

Also in the configuration according to the present embodiment, it is possible to realize a high-quality image display corresponding to the curved screen S as in the above-described embodiment.

<Other Embodiments>
The present technology is not limited to the embodiments described above, and various other embodiments can be realized.

As shown in the graphs of FIGS. 13 and 24, it can be seen that the curvature of the concave reflecting surface Mr3 according to the first and second embodiments increases from 0.9 to 1.00 the height of the light beam. Focusing on this, one feature of the concave reflecting surface Mr3 according to the present technology can be defined by the following conditional expression.
That is, the projection optical system is configured so as to satisfy the following relationship: 1 <<Z'(1.0 · hmax) −Z'(0.9 · hmax) | / | Z'(0.7 · hmax) ) -Z'(0.5 · hmax) | <20
1 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'(0.5 · hmax) -Z'(0.3 · hmax) | <20

These equations are conditional equations given based on the feature that the shape change due to the ray height of 0.9 to 1.00 is larger than the range of other ray heights. The projection optical system according to the present technology may be configured by using these conditional expressions.

FIG. 26 is an optical path diagram showing a schematic configuration example of a projection optical system according to another embodiment. In this projection optical system 315, the planar reflection surface Mr4 is arranged between the first optical system L1 and the concave reflection surface Mr3 which is the second optical system L2. The plane reflecting surface Mr4 bends the optical path traveling direction of the first optical system L1. Such a configuration may be adopted.

Even in such a case, the concave reflecting surface Mr3 may be appropriately configured with the bent optical axis O'as a reference axis. That is, the concave surface is such that at least a part of the light rays contained in the image light incident on the concave reflection surface Mr3 is reflected in the direction intersecting the direction along the optical axis O', which is the reference axis, at an angle of 80 degrees or more. The reflective surface Mr3 is configured. In other words, the concave reflection surface Mr3 is configured so that there is a light ray having an intersection angle θ1 shown in FIG. 26 of 80 degrees or more. In FIG. 26, the intersection angle θ1 of the pixel light C4 (not shown) is configured to be 80 degrees or more.

27 and 28 are schematic views showing a configuration example of an image display system according to another embodiment. In the image display system 400 shown in FIG. 27, a curved screen S having a dome shape is used. The dome shape is not limited to the hemispherical shape, and includes any shape that can cover the upper part over a circumference of 360 degrees.

As shown in FIGS. 27A to 27C, the first and second image display devices 420a and 420 are installed below the dome-shaped curved screen S so as to face each other in the left-right direction. The first and second image display devices 420a and 420b are installed so that the first and second images 421a and 421b can be projected upward, respectively.

The first and second images 421a and 421b are projected so as to overlap each other along the long side direction (horizontal direction). Therefore, an overlapping region 422 in which the first and second images 421a and 421b overlap each other is generated at the apex portion of the curved screen S. The stitching process is executed with the overlapping area 422 as a reference, and one large image is displayed.

By using the image display devices according to the present technology described above as the first and second image display devices 420a and 420b, it is possible to realize high-quality image display corresponding to the dome shape, and to provide an excellent viewing environment. It will be possible to provide.

In the image display system 500 shown in FIG. 28, the first to third image display devices 520a to 520b are arranged at equal intervals along the circumference below the dome-shaped curved screen S. The first to third image display devices 520a to 520c are installed so that the first to third images 521a to 521c can be projected upward.

As shown in FIG. 28B, as the first to third images 521a to 521c, image light for forming a rectangular image is projected. In FIG. 18B, each of the first to third images 521a to 521c is schematically shown in a rectangular shape, but the shape displayed on the curved screen S is different from the rectangular shape.

The first to third images 521a and 521b are projected so as to overlap each other at positions symmetrical with respect to the vertices of the curved screen S. Then, the stitching process is executed in the overlapping areas 522a to 522c, and one large-sized image is displayed.

By using the image display devices according to the present technology described above as the first to third image display devices 520a to 520c, high-quality image display corresponding to the dome shape can be realized, and an excellent viewing environment can be achieved. It will be possible to provide. As described above, this technique can be applied even when three or more image display devices are used.

As the concave reflecting surface that reflects the image light on the screen, a free curved surface having no axis of rotational symmetry may be used. In this case, for example, the optical axis of the concave reflecting surface (for example, the axis passing through the center of the optical surface) is aligned with the reference axis that serves as a reference in forming the lens system. The concave reflecting surface is appropriately designed so that at least a part of the light rays contained in the image light is reflected in the direction intersecting the direction along the reference axis at an angle of 80 degrees or more. This makes it possible to exert the same effect as described above.

The projectile is not limited to a curved screen. This technology can be applied to display an image on an arbitrary object such as a table or a wall of a building. In particular, it is possible to realize a high-quality image display corresponding to a projectile having a curved surface shape.

Each configuration of the image display system, the image display device, the projection optical system, the concave reflective surface, the screen, etc. described with reference to each drawing is only one embodiment, and can be arbitrarily modified as long as the purpose of the present technology is not deviated. It is possible. That is, other arbitrary configurations, algorithms, and the like for implementing the present technology may be adopted.

In the present disclosure, "match", "equal", "vertical", "rectangular", "dome shape", "symmetrical", etc. are "substantially coincident", "substantially equal", "substantially vertical", and "substantially rectangular". The concept includes "shape", "substantially dome shape", and "substantially symmetric". For example, within a predetermined range (for example, ± 10% range) based on "perfect match", "perfect equality", "perfect vertical", "perfect rectangular shape", "perfect dome shape", "perfect symmetry", etc. The included state is also included.

It is also possible to combine at least two feature parts among the feature parts according to the present technology described above. That is, the various feature portions described in each embodiment may be arbitrarily combined without distinction between the respective embodiments. Further, the various effects described above are merely examples and are not limited, and other effects may be exhibited.

The present technology can also adopt the following configurations.
(1) Light source and
An image generator that modulates the light emitted from the light source to generate image light,
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It is provided with a projection optical system that is configured with the reference axis as a reference and has a concave reflecting surface that reflects the image light emitted from the lens system toward an object to be projected.
The concave reflecting surface is an image display device that reflects at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more.
(2) The image display device according to (1).
The image light includes a plurality of pixel lights and includes a plurality of pixel lights.
The concave reflecting surface is an image display device that reflects at least one pixel light out of the plurality of pixel lights in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more.
(3) The image display device according to (1) or (2).
The angle at which the traveling direction of each light ray included in the image light reflected by the concave reflecting surface intersects with the direction along the reference axis is set to θ1, and the angle θ1 of the light ray having the largest angle θ1 is set to θ1max. Then,
An image display device configured to satisfy the relationship of 80 degrees ≤ θ1 max ≤ 160 degrees.
(4) The image display device according to any one of (1) to (3).
The concave reflecting surface is configured so that the axis of rotational symmetry coincides with the reference axis.
The height of the light beam from the reference axis is h, the derivative of the function Z (h) representing the shape of the concave reflecting surface according to the height of the light beam is differentiated by the height of the light ray, and the derivative is Z'(h). The ray height corresponding to the reflection point farthest from the reference axis is hmax, and the average value of Z'(h) from the reference axis to the ray height hmax is Z'ave. Then
1 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | <20
An image display device that is configured to satisfy the relationship.
(5) The image display device according to any one of (1) to (4).
The reference axis is an image display device that extends the optical axis of the lens closest to the image generation unit included in the lens system.
(6) The image display device according to any one of (1) to (5).
The lens system is an image display device configured such that the optical axes of one or more optical components included in the lens system coincide with the reference axis.
(7) The image display device according to any one of (1) to (6).
The concave reflecting surface is an image display device configured such that the optical axis of the concave reflecting surface coincides with the reference axis.
(8) The image display device according to any one of (1) to (3) and (5) to (7).
The concave reflecting surface is an image display device having a free curved surface having no axis of rotational symmetry.
(9) A projection optical system that projects image light generated by modulating the light emitted from a light source.
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It is configured with the reference axis as a reference, and includes a concave reflecting surface that reflects the image light emitted from the lens system toward the object to be projected.
The concave reflecting surface is a projection optical system that reflects at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more.
(10) (A) Projected object and
(B) Each
Light source and
An image generator that modulates the light emitted from the light source to generate image light,
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It has a projection optical system that is configured with reference to the reference axis and has a concave reflecting surface that reflects the image light emitted from the lens system toward the object to be projected.
The concave reflecting surface is one or more images that reflect at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction intersecting a direction along the reference axis at an angle of 80 degrees or more. An image display system including a display device.
(11) The image display system according to (10).
The image generation unit has an image modulation element that emits the image light, and has an image modulation element.
Each of the image modulation elements has a plurality of pixels that emit pixel light, and emits the image light including the plurality of pixel lights emitted from the plurality of pixels.
The optical path length of the pixel light emitted from the pixel closest to the reference axis of the image modulation element to the object to be projected is Lp1, and the pixel closest to the reference axis is on a straight line connecting the central pixel of the image modulation element. Let Lp2 be the optical path length of the pixel light emitted from the pixel farthest from the reference axis to the object to be projected.
0.005 <Lp1 / Lp2 <0.5
An image display system that is configured to satisfy the relationship.
(12) The image display system according to (10) or (11).
Let Ln be the optical path length of the light ray having the shortest optical path length to the object to be projected, and Lf be the optical path length of the light ray having the longest optical path length among the light rays included in the image light.
0.005 <Ln / Lf <0.5
An image display system that is configured to satisfy the relationship.
(13) The image display system according to any one of (10) to (12).
The projectile is a curved screen.
Each of the one or more image display devices is an image display system in which the concave reflecting surface is arranged at a position corresponding to the shape of the curved screen.
(14) The image display system according to any one of (10) to (13).
The one or more image display devices include a first image display device that projects a first image onto the curved screen, and a second image display device that projects a second image onto the curved screen.
The first image display device and the second image display device project the first image and the second image, respectively, so that the first image and the second image overlap each other. Display system.
(15) The image display system according to (14).
The first image display device and the second image display device are such that the image lights forming a region other than the region where the first image and the second image overlap each other do not intersect with each other. An image display system that projects the first image and the second image, respectively.
(16) The image display system according to (14) or (15).
The image generation unit generates the image light that constitutes a rectangular image, and generates the image light.
In the first image display device and the second image display device, the first image and the second image overlap each other along the long side direction of the first image and the second image. As described above, an image display system that projects the first image and the second image, respectively.
(17) The image display system according to (14) or (15).
The image generation unit generates the image light that constitutes a rectangular image, and generates the image light.
In the first image display device and the second image display device, the first image and the second image overlap each other along the short side direction of the first image and the second image. As described above, an image display system that projects the first image and the second image, respectively.
(18) The image display system according to any one of (10) to (17).
The projectile is an image display system that is a screen having a dome shape.
(19) The image display system according to any one of (10) to (18).
The one or more image display devices are image display systems including three or more image display devices.

C1 to C4 ... Pixel light L1 ... First optical system L2 ... Second optical system Mr3 ... Concave reflective surface 1 ... Liquid crystal projector 5 ... Light source 10 ... Illumination optical system 15, 215, 315 ... Projection optical system 20
20a, 420a, 520a ... First image display device 20b, 420b, 520b ... Second image display device 21a, 421a, 521a ... First image 21b, 421b, 521b ... Second image 22, 422, 522a ~ c ... Overlapping area 23a ... First image light 23b ... Second image light 30, S ... Curved screen 100, 400, 500 ... Image display system 520c ... Third image display device 521c ... Third image display device

Claims (19)

Light source and
An image generator that modulates the light emitted from the light source to generate image light,
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It is provided with a projection optical system that is configured with the reference axis as a reference and has a concave reflecting surface that reflects the image light emitted from the lens system toward an object to be projected.
The concave reflecting surface is an image display device that reflects at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more. The image display device according to claim 1.
The image light includes a plurality of pixel lights and includes a plurality of pixel lights.
The concave reflecting surface is an image display device that reflects at least one pixel light out of the plurality of pixel lights in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more. The image display device according to claim 1.
The angle at which the traveling direction of each light ray included in the image light reflected by the concave reflecting surface intersects with the direction along the reference axis is set to θ1, and the angle θ1 of the light ray having the largest angle θ1 is set to θ1max. Then,
An image display device configured to satisfy the relationship of 80 degrees ≤ θ1 max ≤ 160 degrees. The image display device according to claim 1.
The concave reflecting surface is configured so that the axis of rotational symmetry coincides with the reference axis.
The height of the light beam from the reference axis is h, the derivative of the function Z (h) representing the shape of the concave reflecting surface according to the height of the light beam is differentiated by the height of the light ray, and the derivative is Z'(h). The ray height corresponding to the reflection point farthest from the reference axis is hmax, and the average value of Z'(h) from the reference axis to the ray height hmax is Z'ave. Then
1 <<Z'(1.0 · hmax) -Z'(0.9 · hmax) | / | Z'ave. | <20
An image display device that is configured to satisfy the relationship. The image display device according to claim 1.
The reference axis is an image display device that extends the optical axis of the lens closest to the image generation unit included in the lens system. The image display device according to claim 1.
The lens system is an image display device configured such that the optical axes of one or more optical components included in the lens system coincide with the reference axis. The image display device according to claim 1.
The concave reflecting surface is an image display device configured such that the optical axis of the concave reflecting surface coincides with the reference axis. The image display device according to claim 1.
The concave reflecting surface is an image display device having a free curved surface having no axis of rotational symmetry. A projection optical system that projects image light generated by modulating the light emitted from a light source.
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It is configured with the reference axis as a reference, and includes a concave reflecting surface that reflects the image light emitted from the lens system toward the object to be projected.
The concave reflecting surface is a projection optical system that reflects at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction that intersects a direction along the reference axis at an angle of 80 degrees or more. (A) Projected object and
(B) Each
Light source and
An image generator that modulates the light emitted from the light source to generate image light,
A lens system that is configured with reference to the reference axis at the position where the generated image light is incident and has a positive refractive power as a whole.
It has a projection optical system that is configured with reference to the reference axis and has a concave reflecting surface that reflects the image light emitted from the lens system toward the object to be projected.
The concave reflecting surface is one or more images that reflect at least a part of light rays contained in the image light incident on the concave reflecting surface in a direction intersecting a direction along the reference axis at an angle of 80 degrees or more. An image display system including a display device. The image display system according to claim 10.
The image generation unit has an image modulation element that emits the image light, and has an image modulation element.
Each of the image modulation elements has a plurality of pixels that emit pixel light, and emits the image light including the plurality of pixel lights emitted from the plurality of pixels.
The optical path length of the pixel light emitted from the pixel closest to the reference axis of the image modulation element to the object to be projected is Lp1, and the pixel closest to the reference axis is on a straight line connecting the central pixel of the image modulation element. Let Lp2 be the optical path length of the pixel light emitted from the pixel farthest from the reference axis to the object to be projected.
0.005 <Lp1 / Lp2 <0.5
An image display system that is configured to satisfy the relationship. The image display system according to claim 10.
Let Ln be the optical path length of the light ray having the shortest optical path length to the object to be projected, and Lf be the optical path length of the light ray having the longest optical path length among the light rays included in the image light.
0.005 <Ln / Lf <0.5
An image display system that is configured to satisfy the relationship. The image display system according to claim 10.
The projectile is a curved screen.
Each of the one or more image display devices is an image display system in which the concave reflecting surface is arranged at a position corresponding to the shape of the curved screen. The image display system according to claim 10.
The one or more image display devices include a first image display device that projects a first image onto the curved screen, and a second image display device that projects a second image onto the curved screen.
The first image display device and the second image display device project the first image and the second image, respectively, so that the first image and the second image overlap each other. Display system. The image display system according to claim 14.
The first image display device and the second image display device are such that the image lights forming a region other than the region where the first image and the second image overlap each other do not intersect with each other. An image display system that projects the first image and the second image, respectively. The image display system according to claim 14.
The image generation unit generates the image light that constitutes a rectangular image, and generates the image light.
In the first image display device and the second image display device, the first image and the second image overlap each other along the long side direction of the first image and the second image. As described above, an image display system that projects the first image and the second image, respectively. The image display system according to claim 14.
The image generation unit generates the image light that constitutes a rectangular image, and generates the image light.
In the first image display device and the second image display device, the first image and the second image overlap each other along the short side direction of the first image and the second image. As described above, an image display system that projects the first image and the second image, respectively. The image display system according to claim 10.
The projectile is an image display system that is a screen having a dome shape. The image display system according to claim 10.
The one or more image display devices are image display systems including three or more image display devices.

Images